基于Micro-CT技术的3D机织预制件细观结构分析

Analysis of meso-structure of 3D woven preforms based on the micro-CT technology

基于微计算机断层扫描(Micro-CT)技术重构了纤维预制件的3D细观结构,提出了两个表征纤维预制件几何结构变形的量化指标,研究了纬纱密度和厚度对3D机织预制件细观结构的影响机制。结果表明:Micro-CT技术能够有效表征3D机织预制件内部纱线的截面形态和空间路径;当纬纱密度为2.0根/cm时,预制件试样均表现出明显的变形,不适合实际工程应用;随着纬纱密度的增加,纤维预制件的内部结构趋于稳定;10 mm试样的内部结构比5 mm试样更稳定,但表面纱线的横截面和路径仍然呈现较大的变形。

The 3D meso-structures of the fiber preforms was reconstructed based on the micro-computed tomography(micro-CT)technology,two quantitative indexes were proposed to characterize the deformation of the fiber preforms'geometric structure.The influence mechanism of weft densities and thicknesses on the meso-structure of the 3D woven preform was studied.The results show that the micro-CT technology can be used to characterize the cross-section and spatial path of the yarns inside the 3D woven preform effectively.The preform samples with the weft density of 2.0 picks/cm show obvious deformation,and thus are not suitable for practical engineering application.With the increase of the weft density,the internal structure of the fiber preform tends to be stable.The internal structures of the 10 mm samples are more stable than that of the 5 mm samples,however,the cross section and path of the surface yarns still show large deformation.